So, if a carrier is able to host 40 crafts (not worrying about the mix for the time being). If, say, 10 are expected for CAP duty. Then what does it matter if 10 are LCA (tiny) or MiG-29 (large)? As long as the remaining are MiG-29s it should not matter. Right? Or am I still missing something?

Where it would matter is if 10 are required for CAP and 20 LCAs are placed. Or even if the original mix of 10 LCA and rest MiG-29 are maintained, but they send 5 MiG-29 for CAP, when they can replace them with MiG-29s.

???????

NRao,

Clearly the operating cost is an important factor. And the limit of 40? is imposed by size, weight, and stores --including fuel.

Also, Max. air wing on vik. appears to be 30 fixed wing. Presume that includes using all the deck parking as well. Not sure if they have storage for all 30+6 rotary beneath deck. 6 rotary also seems like they will be 1-2 SAR + 4 radar pickets. No space for anything medium weight.

If the role is suitable for smaller aircraft then why not have half the area open, to work on things. A factor of approx. 2 is not a small difference. There are obvious savings, so what is the downside?

What on earth do you need 40 AC for?? I would expect 6 rotating CAP and maybe 12 for strike missions. Keep 2 in spare.

Lets evaluate the utility of the carrier. at 18 craft -- 18 launches/18 recoveries, its an event every two minutes. Seems like a busy day. But statistics are deceptive.

Assume a 2 week war, 24 hour cycle, 100% aircraft availability without losses kept up with crew rotations. Impossible. But what can the carrier contribute at this rate? Daily sorties -- 12×24 =288.

Over 14 days, approx 4000. 4000 is not a lot of targets by themselves over 2 weeks. Wont keep a whole lot of defenders busy.

When IAF was not a central role, there were still 550 sorties needed for safed sagar. In a pretty target barren terrain. You expect an order of magnitude larger number available in a full on conflict. None avoidable unlike safed sagar.

With 24 craft, you cut down the sorties rate of individual aircraft, still keep up the tempo even with 50% availability, or work at peak rates with lower crew size. So on.

Not everything has to be up and available all the time if its 24. With 12 the margin is pretty thin, you run out of options pretty fast due to crew, maintenance, etc. Realistic numbers are a fraction of the theoretical maximum.

These numbers eventually decide the role for the carrier. Is it just for knocking out karachi in an eventuality or a multi purpose device.

ps -- this is getting tangential to LCA, so I bow out ahead of mullahs. Please ask the navy thread how they see the usage of the whole group for further insights.

edit --folded up at 7.8m, the 29k takes 130sqm. Not quite twice, but still not the same as NLCA. Two triangles back to back make a square. Overall loaded weight is a constant for the ship. Still nothing negative for the single engine, even if not a 100% space savings.

I was responding ot teh original post that stated that a MK-I would free up a longer legged MiG-29.

So, let us take the 30 planes you mention (I picked 40 out of thin air - only as an example). So, FOR CAP, you replace let us say 5 MiG-29s (that you would use for CAP) with LCAs - one for one swap. So, now you have 5 LCA (for CAP) and still 25 MiG-29s for "longer legged" work - which you already had.

So what gives?

Going with your Vick example, so, it carries 30 MiG-29 (war conditions). So, what would you suggest the IN do to make the CAP situation better?

What on earth do you need 40 AC for?? I would expect 6 rotating CAP and maybe 12 for strike missions. Keep 2 in spare.

(No where close to an expert.)

IF, India wants to project into the SCS, then I would expect India to field a couple of 80 air craft carriers. 80-90K tons. with the full complement - AWACS and all. even for projection within IOR there should be a need for larger carriers than the ones proposed.

I was responding ot teh original post that stated that a MK-I would free up a longer legged MiG-29.

So, let us take the 30 planes you mention (I picked 40 out of thin air - only as an example). So, FOR CAP, you replace let us say 5 MiG-29s (that you would use for CAP) with LCAs - one for one swap. So, now you have 5 LCA (for CAP) and still 25 MiG-29s for "longer legged" work - which you already had.

So what gives?

Going with your Vick example, so, it carries 30 MiG-29 (war conditions). So, what would you suggest the IN do to make the CAP situation better?

You save on fuel/maintenance in the one for one swap, and also have 2 29k worth of storage space available. 2/30 is a measurable fraction in terms of the tight space. If it costs less, you train with it more often too.

If fuel/stores are available, I would assume the overall impact of smaller aircraft would be a greater number carried overall. Not just a one/one swap. Perhaps Navy thread on where the NLCA fits if 10 were on the deck?

No reason for a one to one swap. Or space saved adds to the strike element.

The LCA doesnt fold, and even folded up nothing takes away the length disadvantage 13m vs 17m for the 29k. So not sure how there could be fewer LCAs. Its a much smaller craft.

As you said CAP is CAP, so the 2 hours is what matters. On a one to one basis you save only money. May be stretch you aviation fuel supplies.

edit -- an inherent assumption here is also that the number of 29k imported is a constant and can only go down or is redirected to another role. The number of NLCA is not constant and can only go up. What becomes free serves off land, or different ship.

Why are we assuming that NLCA-mk-II cannot have folded wings? Does only russians know how to fold wings? So it is quite possible to fold up the NLCA-mk-II wings and again bring it to 2:1 (LCA:Mig29k) advantage.

That should answer NRao's question - that taking 5 Mig 29k out, you can have 10 N-LCA-mkII (with folded wings) doing a CAP (and *assuming* all things remaining the same) you have twice as many at your hands doing CAP freeing up Mig 29k for better purposes (where those 5 Migs are on say Shore or another Carrier - as Shreeman pointed out)

Okay so let us come back to NLCA-mk-1 - and as Shreeman points out, it still has the length advantage - maybe a 1.5:1 ratio of replacement. Still that frees up some Mig 29k. It is definitely not 1:1 replacement for Mig 29k. So instead of 30 Mig 29k - with 5 for CAP and 25 for strike, you may end up with 25 for strike and 7 for CAP if 5 Mig 29k are replaced with 7 NLCA-mk1. Assuming the defensive capacity of LCA is same vis-a-vis Mig29k, the defensive capacity in this case is enhanced.

Now, given that a quarter of Su-30 MKI is on ground at any time (for repairs, upgrades, maintenance etc) - why cannot that be expected of Mig 29ks? On a wartime basis, it is not improbable to see a plane cannibalized to provide parts to other planes. So one can think of 25 for strike, 1 for spare ( ) and 5 LCAs for CAP. Assuming that there NLCAs are equally capable in defense as Mig 29k, the offensive/defensive capacity remains the same with a better turnaround.

My point is simple, a mix of small and large fighters will lead to an optimal usage of both!!

Added later: Looking at the fotu, there is considerable vertical space. Maybe a mumbai style parking lot can be had for the planes. That is, alternate ramps to raise the adjacent planes higher and pack it more closely.

disha wrote:Why are we assuming that NLCA-mk-II cannot have folded wings? Does only russians know how to fold wings? So it is quite possible to fold up the NLCA-mk-II wings and again bring it to 2:1 (LCA:Mig29k) advantage.

I am not an expert, but could it be because of LCA being a delta-winged aircraft and as such it maybe more difficult and complex to design folded delta wings. I believe Rafale M, despite being equipped for carrier takeoff and landing is also a fixed delta wing aircraft.

Another naval aircraft with a delta wing that didn't require any wing folding was the Rafale M. The Rafale M didn't require folded wings since the actual production aircraft shrunk in size compared to the demonstrator and its wing span was considered small enough to not need wing folding.

What on earth do you need 40 AC for?? I would expect 6 rotating CAP and maybe 12 for strike missions. Keep 2 in spare.

Lets evaluate the utility of the carrier. at 18 craft -- 18 launches/18 recoveries, its an event every two minutes. Seems like a busy day. But statistics are deceptive.

Assume a 2 week war, 24 hour cycle, 100% aircraft availability without losses kept up with crew rotations. Impossible. But what can the carrier contribute at this rate? Daily sorties -- 12×24 =288.

Over 14 days, approx 4000. 4000 is not a lot of targets by themselves over 2 weeks. Wont keep a whole lot of defenders busy.

When IAF was not a central role, there were still 550 sorties needed for safed sagar. In a pretty target barren terrain. You expect an order of magnitude larger number available in a full on conflict. None avoidable unlike safed sagar.

With 24 craft, you cut down the sorties rate of individual aircraft, still keep up the tempo even with 50% availability, or work at peak rates with lower crew size. So on.

Not everything has to be up and available all the time if its 24. With 12 the margin is pretty thin, you run out of options pretty fast due to crew, maintenance, etc. Realistic numbers are a fraction of the theoretical maximum.

These numbers eventually decide the role for the carrier. Is it just for knocking out karachi in an eventuality or a multi purpose device.

ps -- this is getting tangential to LCA, so I bow out ahead of mullahs. Please ask the navy thread how they see the usage of the whole group for further insights.

edit --folded up at 7.8m, the 29k takes 130sqm. Not quite twice, but still not the same as NLCA. Two triangles back to back make a square. Overall loaded weight is a constant for the ship. Still nothing negative for the single engine, even if not a 100% space savings.

Fighter wing of an aircraft carrier isn't exactly meant for CAP duty. It's primary use is anti-shipping, ground attack and related anti-air roles. What's the logic of having aircraft on an aircraft carrier which can only perform CAP duties ?

I think we should get some of our expectations from NLCA Mk1 right. Otherwise, you will read lots of news with headlines like "DRDO-made NLCA cannot be operated from Indian ships".

1. Role of aircraft on IN aircraft carriers1.a. The aircrafts are the AC's best defensive system. They are the most flexible and the most potent. In the Indian Navy (AFAIK), the primary role of the aircrafts is to defend the carrier group against all aerial attacks. 1.b. Having said that the Mig-29K, NLCA are truly multirole aircraft which can be used for offensive roles suck as anti-ship and coastal strike.

2. Expectations from NLCA-Mk12.a. Given its TWR, it can either launch from a skijump with either sufficient payload or sufficient fuel. This might still be better than STOVL aircraft like the Harrier, but for an aircraft carrier which can handle the Mig-29K with better TWR and fuel-fraction, NLCA Mk1 will probably never be fielded from Vikramaditya and all future aircraft carriers. That's why they have got 45 Mig-29Ks for 2 aircraft carriers. Even when Mk2s are supposed to be fielded on the ACs. 2.b. NLCA Mk1 is a very important program. All fighter programs which have tried to adopt an airforce version of a fighter to a naval variant have realized that the planes are essentially different beasts. The designer of Su-27K realized this and used to call it Su-33 (unofficially) as he thought it was a completely different fighter from the Su-27. J-15 was favoured over a J-11 naval variant as converting the latter was thought to be much more (technically) risky proposition. If we had started with the conversion of LCA Mk2, it would have taken so much time. Instead all those technological challenges are being overcome on NLCA Mk1 itself, and will be taken as is to Mk2.2.c. NLCA Mk1 is also a great trainer aircraft.

3. Advantages of NLCA-Mk23.a. NLCA-Mk2 will have the right TWR for carrying enough fuel and payload off the ski jump. It will have a good fuel fraction to have sufficient "staying" capability for many roles. For heavier payload delivery the Mig-29K can be used. 3.b. NLCA Mk2 does not need folding wings. Its wingspan is already quite small. 3.c. Each aircraft carrier can carry about 4 NLCA to every 3 Mig-29K (may be 5 to every 4). Similarly, a single Mig-29K with buddy-refueling can top-off more NLCAs for far flung operations. These 2 things combined can give superior numerical advantage with NLCA Mk2s. 3.d. I think greater flexibility can be achieved if NLCAs can also buddy-refuel Mig-29Ks. This will be useful when numerical advantage is not sought but a greater payload carrying capability is sought. The Mig-29Ks can take off with maximum ordinance and be topped off by NLCAs to continue the mission.

perhaps the most vulnerable point in an AC. a buster weapon will not only destabilize the AC, but also make it totally non-operational. wonder if we would have one such ASM wala in any inventory anywhere in the world. /OT

^^ Excellent summation of NLCA role above. This is particularly useful when DDM will go to town screaming and doing their Rhona-Dhona on how NLCA-mkI will not be used because of severe shortcomings onleee ....

Personally, I like NLCA more. It looks like a baby plane with a mischief up its sleeve and of course can kick sideways with its strong legs and flip bandar over ...

jamwal wrote:...What's the logic of having aircraft on an aircraft carrier which can only perform CAP duties ?

Role played by INS Vikrant in 1971 should be a good reference for us.

Jamwal'ji., of course INS Vikrant's 71 ops should be studied and is a good reference. However I hope you are not saying to fight a 2021 war using 1971 tactics!

A better reference for what I am thinking should be HMS Sheffield and Exocet or USS Stark. More discussions on this is apt in Navy thread.

SaiK wrote:with the new gov policies, i would expect FOC and phased dev get a big boost! i'd not be surprized if rafale is canceled!

I would also like ADA/HAL to fly Mk2 prototypes as soon as possible. Get the airframes in the air ASAP. Use balasts for all LRUs which are not ready. The LRUs can be retrofitted even after the planes have been fielded. In fact, they will have so much more time to incorporate IAF's feedback! This is the global norm: look at the Super Hornet the NG. Here is a well chronicled development schedule of the Gripen NG by ex. Cmde Parvez Khokhar (my comments in red):

Early 2006: Demonstrator development started in Saab with the aim to fly in 2008

27 May 2008: Maiden flight of the Demonstrator(NG). This segment of the test programme was concluded in only 79 test flights with the new engine (414), larger internal fuel tank and more pylons (increased payload). (3 years for first flight)!

27 October 2009: Introduced AESA (limited version), MAW and SATCOM. Flown and tested in 73 flights including flights with a larger drop tank. Next step planned was to introduce new avionics. (Avionics still not ready, buying time)!

By 19 December 2012 the demo aircraft had accumulated over 250 hours.

15 July 2013: Saab started the assembly of the Next Generation Gripen, the Gripen E. First to be constructed is the front fuselage of the first pre-production test aircraft 39-8.

15 August 2013: Saab claimed they reduced cost and lead time by 60 per cent, thanks to new processes and new supplier strategy

2018: Delivery of first Gripen E planned for the Swedish Air Force. Saab managed the weight issue rather cleverly through extensive use of aluminium alloys and composites for the airframe. The major lesson that this remarkable programme brought was that it is extremely important to work with the customer to achieve success in record time.(Notice how they take 5 years from production start to actual fielding. This is basically to allow time for the LRUs to be ready. Trust me there will be untied knots in 2018. A perfect fighter is a oxymoron. I hope ADA/HAL don't chase this even before fielding the fighter).

Tejas India MRCA facebook page reports - First LCA to be handed over to IAF Today.

PS - I don't know how to post picture here otherwise I would have posted a screenshot from the 'Tejas India's MRCA facebook page' . Apologies for not getting this via a credible link but if this is true, its a great news.

I wonder if zero length take off systems can be adapted to NLCA (Mk-1 or Mk-2) or even Mig29K for an all up configuration of the desired kind. The booster storage should not be such a big deal since you could limit the usage to exigencies only. Since there is a significant take off strip and ski jump available so the booster size should come down but the system itself will have to be a new kind, not the american kind. The Jato bottles too cannot be adopted straight away. Like this http://en.wikipedia.org/wiki/File:P2V_launch_CVB-42_1951.jpg

Off course all jugaad. Best is to have a 100000 ton carrier. Though I would not mind 2 of the 50000 ton ones. I admit I am not good at making choices, they confuse me.

So yesterday, LCA gave a nice but short pre-AeroIndia demo right over the HAL airfield. Flying very low, one horizontal turn and one full vertical turn. Before I could ran to terrace of my office building for better view it went away.

I was so excited to see LCA from so close for the very first time.

Anybody else had any better view??

@Indranil

I read your comments on the Aerodynamics of LCA wing. What do you think of the slight angled setting (LE slightly up than TE at same lateral section) of the inboard section of the wing (the one with lower sweep angle)?? The CFD pictures showing flow pattern that are there in public domain and whatever I have read on BRF in some old posts, I think that portion not only somehow produces canard-like effect but it also, due to this peculiar angled setting, keeps the vortex flow off from the fuselage section from behind the cockpit towards the tail. This helps maintain clean attached flow on central part and attached flow to pass over the tail, so tail/radar can work normally. If LE vortex is allowed to go near the tail it screws up its functioning and irregular vortex busting creates a lot of issues (F-18 had this issue initially, they had to provide brackets to strengthen its tail so that it can sustain the cyclic loads arising from highly unsteady flow coming from the LERX, IIRC). I have been trying to visualise the air flow over that section, the conical-kind of shape it creates, it pushes the vortex interaction away from the center-line. Not only the setting angle of the inboard part, but also lower sweep angle should help in this. if the wing did not had that section with lower sweep and slightly positive setting angle, I think that the vortex interaction would have interfered with the flow on center-line and the tail as well, something like what F-18 had encountered.

HAL is seeking approval from government to ramp up the production rate from 8 to 16 (which means, more orders please). The lead time is approximately 30 months.

As reported in these columns earlier, HAL had submitted a proposal to MoD for augmenting the production of Tejas from eight per year to sixteen. "We have submitted the proposal at the cost of Rs 1200 crore and are hopeful of completing the process in 30 months," an HAL director said. He said the Company is seeking no funding from government for the augmentation of Tejas series production. "We will fund 50 per cent of the total cost with the remaining 25 per cent each expected to come from the IAF and the Navy," he added. Parrikar is also expected to be brief about the record number of patents being filed by HAL in the last 2 years. "In 2012-13 we filed 71 patents and in 2013-14 it stood at 209. In 2014-15 alone we have filed 773 patents and this shows the shift in HAL's focus towards excellence in multiple areas," the director said. HAL is also lining up a flying display of Tejas, Dhruv and LCH for the minister.

Carrier air wing sizing is a complicated problem. The primary determinant is the carrier doctrine (in context of the threats and capabilities of the possible foes): everything else follows from that.

The US aircraft carriers are very capable, but large and expensive. They are tailored to cater to the US carrier doctrine, which is expeditionary warfare. The carrier battle groups expect to be able to strike any target on the planet and exercise air dominance over the battlespace. They are also expected to exert sea denial and be able to beat down any naval foe, including in large fleet-on-fleet action.

In contrast the Soviet carrier doctrine was very different, and based on denying access to the US carriers. The primary weapon in this doctrine was the land-based Backfire with its cruise missiles. The Soviet carriers only existed to provide end-game air-support to the Backfires against opposing fleet air defense. As such, they didn't need to be as large or complex as the US carriers.

The new QE and PoW are "strike carriers", whose primary mission is surface strike. Probably similar to our carriers, but consider what it takes to launch a strike mission against a near-peer opponent.

First, one will need several aircraft to be assembled into a strike package. This will include at a minimum the actual strikers, SEAD/DEAD support, air-support escorts, and EW escort. Some platforms can be multi-tasked, but there are limits. E.g. the strikers can't be completely self-escorting, or else they will have to drop their strike munitions at the first sign of trouble and kill the mission.

These aircraft have to be launched and assembled into a package in the air. Without catapults (and sometimes, even with), one would need to launch with limited fuel and top-up from a tanker. In our context, this would mean that additional airplanes will have to be launched first to serve as the buddy tankers. Note that flight paths to the target are often convoluted to (a) avoid enemy air defence, (b) attack from an unexpected axis and (c) not give away the position of the carrier. All this, plus the vagaries of combat mean that actual combat range will be far below brochure numbers. The returning package may have to be met on their way back and refueled for recovery. Finally, any time an aircraft is launched or recovered, the "Angel" SAR helicopter needs to be launched first. All of this might be happening in less than ideal weather and sea-states, so everything might take longer than you expect.

The kinds of targets and the military capabilities of the opponent will determine how large and complicated the strike package needs to be. The launch rate is pretty much fixed - even the US carriers cannot average more than one launch every 2--3 minutes, and they have multiple catapults and launch positions and dedicated organic tanking. Aircraft on a carrier can't be expected to have the same serviceability as land-based aircraft - they don't have access to the same repair depots, spares, etc. So you have to work backwards to determine how big the carrier air group needs to be to fulfill the mission.

As for CAP, the situation is not as easy as it appears either. The carrier's biggest strength is that it is mobile and cannot be located easily. If one is so silly as to set up CAP orbits centered on the carrier, it would be trivial for the opponent to locate the carrier. CAP orbits have to be offset from the carrier to not give its position away. Neither can the CAP simply be placed at a random distance between the carrier and the shore, because that also discloses the threat axis. Additionally, the CAP needs to be able to deal with off-axis attacks as well, which often means multiple CAP orbits when in a high-threat situation. All these factors go into defining the required strength of the air wing.

Air defence missions for carriers are increasingly being taken away from aircraft. Long range stand-off missiles require that the launch platforms themselves are engaged as part of the layered defence. This used to mean requiring an aircraft like the F-14 which could scream away at Mach 2 and engage a platform with AIM-54 before they launched their missiles. However, this is no longer practical. The anti-ship missiles simply have way too much stand-off range for the launch platforms to be practically engaged by carrier based defences. This mission is now better handled by AAW destroyers with their powerful radars and batteries of SAMs, which can persistently maintain station hundreds of miles away from the carrier itself. (The commanding officer for a CBG's air defence is the captain of one of the escort destroyers, and not on the carrier at all.)

So this all comes back to the question: what is the Indian Navy's carrier doctrine? I had the opportunity to meet a retired IN Vice Admiral (who had commanded Viraat), and asked him this question; he was a little shy and gave nothing away. However, he did mention that the navy uses the carrier in very mission-specific task forces whose composition is determined by the mission in question. So they employ carriers very differently than the CBG of the USN. That being said, he did acknowledge that the Indian carriers are undersized, but this is because of funding considerations and lack of experience in building larger ships. Given the navy's track record, they are probably working on a long-term plan for larger carriers, more capable aircraft and larger air arms, and the current situation with the LCA is the first step of a long process. So the stressing about how many LCAs we can pack into the hangar is probably not super relevant.

sankum wrote:Aircraft taking of from ski jump on a carrier say a 200m run not only depends on TWR but also say approach speed of the aircraft i.e, wing design or say take of speed of aircraft on full load.

If my memory serves right for earlier version of mig 29 take of speed was 125knots, Su27 take of speed was 135knots and rafale approach speed for landing as 115knots and for Nlca mk1 was 120knots.

Mig 29k TWR on full load=18t/24.5t=0.735

Su 33 TWR on full load=25t/30t=0.833

NLCA MK1 TWR on full load=8.56T/12.5t=0.685 given in ADA website and GE website.

NLCA MK1 TWR on full load=9.18T/12.5t=0.7344 if emergency rating for full thrust is 90kn for take off?

NLCA MK2 TWR on full load=10t/13.5t=0.74 based on my estimate (mk1 wing design is taken as that of mk2)

earlier MIG 29K version had MTOW of 22.4t on engine thrust of 17.4T and present has increased wing width of 12m leading to increased MTOW OF 24.5t on engine thrust of 18t.

Mig 29k, NLCAmk1 and NLCAmk2 all have TWR of 0.735.

MiG-29K's Sea Wasp Engines can operate with Max Take-off thrust rating of 10t each. It is used during take-offs alone and not used at altitudes/combat. So that's 20000kgf from both the engines. The Series 3 engines on the land version of the -29 also has a take-off thrust of 8700kgf, 400kgf higher than the normal afterburner of 8300kgf. Use of this super afterburner is time limited too apart from the altitude penalty, hence its use only during the take-off run which lasts only a few seconds and where the air is denser at the ground level.

With a standard take-off configuration of 18.5 tonnes, the T/W when taking off from the carrier is 1.08With the maximum take-off weight configuration of 24.5 tonnes, the T/W is 0.82

However, an IAF official confirmed to OneIndia that the handing over will be a symbolic affair with the aircraft having completed only four flights so far. "It's so far flown by an ADA Test Pilot and there's more work left before it can be handed over," the official said.

^ correct. Iirc, the naval fulcrum is pretty good bang fofor the buck and no wonder the Russians prefer it to the su-33. @ normal takeoff, the 29k can do full internal fuel - 5000kg + 2 R77 + 2Archers + 2 kh 31s + 2 * 250 kg bombs and still have take off twr of greater than 1.0..Fwiw, I have read in some fulcrum literature, Fomin I think, that it can take off at full load of 24000kg.

What do you think of the slight angled setting (LE slightly up than TE at same lateral section) of the inboard section of the wing (the one with lower sweep angle)??

My guess is that the leading consideration for the geometry of the bottom surface of the wing at that location is regulation of oblique shocks forward of the inlet, whose geometry only allows a normal shock at the inlet face.

The normal shock slows supersonic flows to subsonic for the engine, but has poor pressure recovery. The oblique shocks do not slow the flow all the way down to subsonic, but have excellent pressure recovery. So the idea is to use a sequence of oblique shocks followed by a single normal shock.

"I'm fed up of the to-and-fro between us and the builders of the LCA. I'm willing to accept the aircraft right now, as is. I am willing to commit my pilots to start clocking numbers on this machine. We need to spend time learning about it, not fighting about it. I am willing to make that commitment."

It took 10 years of staging! I hope the next batch of afsars are better integrated with platform. delivering to use LCA is actually the milestone 0... now we are in operational neutral state; let the step 1 begin!

• Project Definition Phase (PDP) initiated in August 1983 with a government sanction of Rs. 560 cr for conception of LCA programme.• PDP document submitted to the government in 1988.• In mid 1993 Phase-I of Full Scale Engineering Development (FSED) sanctioned:Rs. 2188 cr sanctioned included Rs Rs 560 cr sanctioned earlier.Scope limited to building and flight testing two Technology Demonstrators only.• First Flight on 4th January 2001 (Less than 8 yrs)• FSED Phase-II sanctioned towards design, development and flight testing of 3 Prototypes and 8 Limited-Series Aircraft at a cost of Rs. 3301.78 cr.• Additional Rs. 2475.78 cr sanctioned In 2010.• The delay in obtaining these sanctions necessitated several design upgrades towards obsolescence management.• All these were addressed making Tejas a state-of-the-art, advanced Four+ Generartion combat aircraft.• Tejas granted Initial Operation Clearance (IOC) on 20th December 2013.

What do you think of the slight angled setting (LE slightly up than TE at same lateral section) of the inboard section of the wing (the one with lower sweep angle)??

I don't think that giving the vortex a spanwise element was the real intention. L.E. vortexes for deltas already have that feature. I don't know F-18's exact problem, but I suspect that this would have been the case if the F-18 had a single vertical tail plane.

Raman wrote:My guess is that the leading consideration for the geometry of the bottom surface of the wing at that location is regulation of oblique shocks forward of the inlet, whose geometry only allows a normal shock at the inlet face.

The normal shock slows supersonic flows to subsonic for the engine, but has poor pressure recovery. The oblique shocks do not slow the flow all the way down to subsonic, but have excellent pressure recovery. So the idea is to use a sequence of oblique shocks followed by a single normal shock.

Better pressure recovery is certainly a reason for the shielded intakes.

I think another reason for the large variation of AoA is load distribution. The AoA change from L.E. to T.E. is to keep the central part of the wing as highly loaded, and the trailing edge as lightly loaded as possible. This lets the tail plane to work freely with minimum trim drag. The change of AoA along the span is to keep the load more towards the root rather than the tip. This, as you know, would decrease induced drag and structural weight. All this is possible because the Tejas has such a large wing that even with these weight redistributions, the wing loading of none of the parts is too high.